Products are commonly packaged in boxes, containers or cartons which may, for example, be formed from a paperboard material. Examples of such boxes, containers or cartons include cereal boxes, milk cartons, butter and margarine boxes and beer and soft drink secondary packaging (e.g., cartons enclosing a plurality of beer or softdrink cans or bottles). For explanatory purposes, the simple term “carton” may be used throughout this description to refer to the general type of boxes, containers or cartons described above.
The process of forming this type of carton typically begins by printing a continuous web of material, e.g., paperboard material, with the particular graphics desired for the package in question. The paperboard material may, for example, have a thickness of between about 0.001 and about 0.040 inch. Before printing, the paperboard material may, for example, be of a brown or grey color. Alternatively, the paperboard material may be bleached or coated so as to exhibit a generally white color. A typical web of paperboard material may, for example, have a length of between about 10,000 and about 30,000 feet and may be wound into a roll format.
To print a web of material, the web of material may be mounted on a reel at one end of a web printing machine. Such a web printing machine typically includes various printing stations, each of the printing stations being adapted to apply a different pattern and color of ink to the web. Each printing station may employ an ink application method such as a gravure or a flexographic method, as is well-known in the web printing industry. As can be appreciated, this type of printing machine will typically have a number of active printing stations equal to the number of graphics colors to be applied to the web. A drying station may also be located after each of the printing stations such that each color pattern will be dried before that portion of the web enters the next printing station.
The end of the web of material may then be threaded through the web printing machine and thereafter rewound onto an output reel at the opposite end of the printing machine. In this manner, the entire web may be fed through the printing machine. Within the printing machine, the graphics for the desired package are repeatedly printed along the web.
After printing is completed, the printed web may be removed from the output reel of the printing machine and transferred to a cutting and scoring machine. Alternatively, the printed web may be cut and scored in-line with the printing machine before being rewound onto the output reel. The cutting and scoring machine cuts the web into a plurality of carton blanks, each of which is registered with the graphics printed in the printing machine. Examples of cutting and scoring machines are generally disclosed in U.S. Pat. No. 4,781,317 and U.S. Pat. No. 4,757,930, both of which are hereby specifically incorporated by reference for all that is disclosed therein. Depending on the design of the particular carton blank, the blank may also be folded or partially folded and glued after completion of the cutting and scoring operation.
The carton blanks may then be shipped to the product filling location. At this filling location, the carton blanks are erected and the desired product inserted. Any necessary final gluing, depending on the type of carton, may also be accomplished at this time. Examples of carton blanks and of cartons formed therefrom are disclosed in U.S. Pat. No. 5,092,516 and U.S. Pat. No. 5,632,404, both of which are hereby specifically incorporated by reference for all that is disclosed therein.